What You Need to Know About Nifedipine
Highlights
- Nifedipine is a calcium channel blocker approved to treat high blood pressure (hypertension) and chest pain (angina).
- Some off-label or non-FDA-approved uses of nifedipine include treating conditions like Raynaud’s phenomenon, pulmonary hypertension, and anal fissures.
- Nifedipine can sometimes cause side effects like dizziness, fatigue, flushed skin, and headaches.
- This medication may not be used by certain people, such as those with heart or liver failure, or people who’ve recently suffered a heart attack.
Nifedipine may be your silent savior in the battle against hypertension and angina.
Over 4 million nifedipine prescriptions were filled in the U.S. in 2020, making this a vital drug for the management of cardiovascular conditions.
If you need to treat high blood pressure or chest pain, keep reading to learn more about nifedipine.
In this article, we’ll explain what nifedipine is, how it can be used, and which steps you can follow to minimize any potential side effects when taking this drug.
What is Nifedipine Used for?
Nifedipine is a calcium channel blocker used to treat hypertension and angina (including Prinzmetal’s angina).
Some off-label (non-FDA-approved) uses for nifedipine include severe hypertension in pregnancy, Raynaud’s phenomenon, and tocolysis (stopping of labor, especially if preterm).
There are other off-label indications that we’ll discuss below.
Key Point: What is Raynaud’s Phenomenon?
This is a condition where the arteries in the hands, and sometimes the feet, go into spasm and narrow. This leads to obstructed blood flow to the hands and feet, causing pain, tingling sensations, coldness, and a white discoloration in the limb the artery supplies.
How Does Nifedipine Work?
As mentioned above, nifedipine is a calcium channel blocker. In the muscle cells of the heart and arteries, calcium acts as a messenger that stimulates muscle contraction.
When this occurs, the arteries throughout the body start to narrow, and blood pressure increases. Therefore, blocking calcium entry into muscle cells decreases blood pressure by opening up arteries.
Conditions like Raynaud’s phenomenon and chest pain (angina) are caused by decreased blood flow to the hands and feet or the heart, due to arteries narrowing. This results in pain.
As nifedipine increases blood flow throughout the body, it also reduces the pain associated with reduced blood circulation.
Nifedipine comes in both regular and extended-release formulations. The regular-release nifedipine — also known as immediate-release nifedipine — needs to be taken more often, and is associated with a more drastic and rapid decrease in blood pressure, and an increased risk of adverse effects.
In its extended-release form, nifedipine has reduced side effects and is proven to decrease blood pressure for 24 hours after a single dose.
What Should You Tell Your Doctor Before Taking Nifedipine?
Before starting nifedipine, it's essential to tell your doctor about the following:
- Current medications: Provide a comprehensive list of all medications you're currently taking, including over-the-counter (OTC) options and dietary supplements.
- Medical history: Disclose any current health issues and detail your past health history, highlighting your allergies, as well as any previous heart attacks, heart problems, strokes, and surgeries you’ve had.
- Pregnancy status: You should always inform your doctor if you’re pregnant or planning to conceive.
Key Point: What are Some Other Uses of Nifedipine?
Aside from those we’ve already mentioned, there are also other uses of nifedipine. Non-FDA-approved uses for nifedipine include:
- Pulmonary hypertension: Nifedipine can be prescribed off-label to treat hypertension that affects the arteries in the lungs and heart.
- Anal fissures: A gel or ointment will typically be prepared by your pharmacist for the treatment of annual fissures. These topical treatments relax the sphincter muscles, improving blood flow to the area, promoting healing.
- Achalasia: This condition causes damage to the nerves in the esophagus, making it difficult for you to swallow. By relaxing the lower esophageal sphincter, nifedipine provides relief to some people with achalasia.
What Should You Know Before Taking Nifedipine?
Because nifedipine can reduce blood pressure rapidly, it is important to remember that any blood pressure medications taken with it are more likely to cause hypotension.
What is hypotension?
This refers to very low blood pressure levels, meaning that there’s not enough blood flow to provide adequate oxygen to vital organs like the brain and heart.
People with hypotension typically have blood pressure that drops to below 90 mmHg systolic (top number) or 60 mmHg diastolic (bottom number). This causes various symptoms.
Symptoms of hypotension include:
- Dizziness, especially when getting up from a sitting or lying position
- Confusion
- Visual disturbances
- Shortness of breath
- Heart palpitations
- Sweating
- Fainting
- Flushed skin: This may be an overlooked symptom as low blood pressure typically causes pale skin. Nifedipine dilates blood vessels in the body to cause decreased blood pressure that results in flushed skin.
If blood pressure drops too low, it can cause a life-threatening condition known as shock. Never ignore symptoms of low blood pressure.
Immediate-release nifedipine may cause low blood pressure
Low blood pressure caused by nifedipine is usually triggered by the immediate-release formulation of the drug.
Caution should be exercised when taking immediate-release nifedipine, as it requires multiple daily doses to regulate blood pressure. Administering doses too close together could lead to an accumulation of the medication in the system.
Always confirm the dose with your doctor and read the packaging to check the formulation of your medication. How to decrease the risk of hypotension when taking nifedipine Nifedipine doses may be adjusted slowly over time to ensure that blood pressure does not drop rapidly.
Your healthcare provider will adjust your medication to the dose that manages your blood pressure with the fewest possible side effects.
Remember, nifedipine should never be stopped suddenly after prolonged use. As is the case with some other blood pressure medications, suddenly stopping nifedipine can cause rebound hypertension – a sudden increase in blood pressure after someone stops taking certain medications.
One study showed that this condition is more common among people with a history of hypertension.
Special dietary requirements when using nifedipine
Some foods can interact with drugs. Always speak to your doctor about dietary adjustments you should make before starting nifedipine and other medications.
Grapefruit interaction
You shouldn’t eat grapefruit or drink grapefruit juice when taking calcium channel blockers like nifedipine.
They increase the amount of nifedipine in the blood, leading to a potential decline in blood pressure or increased side effects.
Typically, drugs taken orally are partially processed by the liver before affecting the body.
The proper use and dosage of nifedipine are determined with this in mind. Grapefruit inhibits this processing by the liver, causing a higher amount of the drug to be available to the body.
High blood pressure and lifestyle factors
Hypertension is often influenced by lifestyle choices. Many conditions, interconnected by lifestyle factors, fall under the umbrella of "metabolic syndrome."
This includes hypertension, elevated blood fat levels, type 2 diabetes, and obesity.
People who are prescribed nifedipine for hypertension often have these and other disorders and may need to make specific dietary adjustments.
Dietary recommendations for these individuals may include reduced sugar, carbohydrate, and sodium intake.
Medication interactions of nifedipine
Nifedipine can interact with various other medications and substances, potentially altering its effectiveness or leading to unpleasant side effects.
Some substances known to interact with nifedipine include:
- Blood pressure medications
- St. John’s Wort — a common herbal remedy for depression and anxiety
- Erectile dysfunction medication, like Viagra® and Cialis®
- Certain psychiatric medications
- Specific HIV medications
- Some antituberculosis drugs
Your doctor will ask you about your current medications, including OTC drugs, supplements, and herbal remedies, before prescribing nifedipine.
This is done to rule out potential drug interactions and to ensure your medication works as intended.
How Should I Use Nifedipine?
The optimal dosage of calcium channel blockers like nifedipine will be determined by your healthcare provider based on how your blood pressure responds to the medication.
Nifedipine extended-release is typically prescribed because only one dose is required per day.
It also has a lower risk of sudden or severe blood pressure drops when compared to immediate-release formulations.
Your health care provider will typically start you on a daily dose of 30 mg nifedipine extended-release.
Do not substitute nifedipine immediate-release for nifedipine extended-release. As previously mentioned, always make sure you have the correct formulation.
Look for nifedipine labeled with abbreviations like XR, CC, XL, or SR, which indicate extended-release versions.
Key Point: What are Some Popular Extended-Release Nifedipine Brands in the U.S.?
The availability of some of the following nifedipine brand names may differ from state to state, but your doctor or pharmacist will prescribe the best one for you:
- Adalat CC®
- Procardia XL®
- Afeditab CR®
- Nifediac CC®
- Nifedical XL®
Important: The immediate-release tablets tend to have different suffixes. Extended-release tablets usually clearly indicate “extended-release” on the packaging.
Pharmacists may give you medication with different packaging or prescribe generic medication, so it is important to always check what you’re taking even if you’ve been using the same treatment for years.
What Should You Do if You Miss a Dose of Nifedipine?
Always take your medication on time. A missed dose of nifedipine can increase your risk of unpleasant side effects and prevent the medication from working as intended. If you’ve missed a dose, take these steps:
-
Call your doctor to ask for advice. You should never adjust your own medication, especially if you can’t check your own blood pressure.
-
If you’re near to the next dose of medication, take your scheduled dose of nifedipine and do not double up to compensate for the missed dose.
-
If you’re able to, check your blood pressure. If your blood pressure is close to or greater than 180 mmHg (systolic) or 120 mmHg (diastolic), call emergency services immediately, especially if you have chest pain, shortness of breath, dizziness, difficulty speaking, facial drooping, or weakness in one side of your body.
-
If there are less than 12 hours before your next dose, take the medication as soon as you remember. If not, skip the dose and take the next scheduled dose. Always monitor yourself for symptoms of high or low blood pressure. This only applies to nifedipine extended-release.
What are the Side Effects of Nifedipine?
Nifedipine (like other medications) can have a range of adverse effects on the body.
It's crucial to distinguish between common side effects and more serious reactions that may require urgent medical attention.
Common side effects of nifedipine
- Dizziness, especially upon standing up rapidly
- Visual disturbances, such as blurry vision, or seeing stars, flashing lights, and strange colors
- Fatigue
- Weakness
- Flushing or redness of the skin
- Swollen legs
- Headache
Serious side effects of nifedipine
- Hypotension and shock
- Chest pain or discomfort
- Signs of an allergic reaction, such as hives, difficulty breathing, or swelling of the face, lips, tongue, or throat
- Confusion or disorientation
- Symptoms that resemble a stroke, including facial drooping, weakness on one side of the body, or slurred speech
If you or someone you know is experiencing any of the serious effects, seek emergency medical attention immediately.
Key Point: What Should I Do if I’ve Overdosed on Nifedipine?
An overdose of nifedipine is a medical emergency that can lead to severe hypotension, an irregular heart rate, and other life-threatening complications.
Here’s what to do if you suspect you’ve overdosed:
- Call 911 immediately and do not attempt to drive yourself to the hospital.
- Call someone you trust and ask them to stay with you in case your condition worsens.
- Lie down with your feet up.
- Always be open and honest with your healthcare provider about the reason for your overdose. Remember — they are there to help, not judge you.
Who Should Not Be Using Nifedipine?
Before starting nifedipine, it's crucial to ensure it's the right fit for you. Here are some conditions and situations where nifedipine may not be advised:
- Allergy to nifedipine: If you've previously had an allergic reaction to this medication
- Active heart attack: If you’re currently experiencing a heart attack or you’ve recently experienced one
- Heart failure: Where the heart doesn't pump blood as well as it should
- Liver failure: The liver plays a role in processing nifedipine, therefore impaired liver function can lead to unpredictable and potentially severe responses to the medication, including substantial blood pressure drops or worsened side effects
- If you have aortic stenosis (narrowing of the aorta) or low blood pressure
What are Some Nifedipine Alternatives?
If you fall into one of the above-mentioned categories or nifedipine is unavailable, your doctor may prescribe one of the following medications:
- Other calcium channel blockers
- ACE-inhibitors
- Angiotensin receptor blockers
- Alpha-blockers
- Aldosterone receptor antagonists
- Diuretics (“water tablets”)
- Beta blockers
Consult your health care provider to help determine which treatment is best for your needs.
Where Can I Get a Prescription for Nifedipine?
Struggling with high blood pressure or angina? Schedule a consultation with a licensed medical professional through LifeMD.
A healthcare provider can prescribe the appropriate treatment for your condition. Book your appointment today.
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